Flap warming improves intraoperative indocyanine green angiography (ICGA) assessment of perfusion. An experimental study.

BACKGROUND: Indocyanine green angiography (ICGA) is slowly replacing conventional methods of evaluating perfusion during flap surgery. Microcirculatory changes during flap elevation create a marked state of hypoperfusion intraoperatively leading to ICGA underestimation of tissue viability and consequent resection of viable tissue. We propose a novel method of flap warming to induce maximum vasodilation before performing ICGA to increase accuracy in assessing perfusion. METHODS: Submental flaps harvested on a single perforator were created in 8 pigs. ICG angiography was performed in the intraoperative phase (ICGA-C), after inducing maximum vasodilatation by warming the flap at 42 °C (ICGA-W) and at 24H postoperative (ICGA-24). By setting a fluorescence threshold of 33% as indicative of necrosis, the flap surface deemed viable by ICGA was measured for ICGAC, ICGAW and ICGA24. The results were then compared to the actual flap survival observed clinically at 7 days. RESULTS: The mean of ICG-C predicted flap survival (FS-C = 49.17%) is 12.97% lower than the mean of actual flap survival on postoperative day 7 (FS = 62.14%). The mean difference between ICG-W and ICG-24 predicted flap survival (FS-W and FS-24) and actual flap survival in the postoperative day 7 (FS) is lower, 3.13% and 2.15%, respectively. Average perfusion recovery over 24 h was 10.83% (FS-24-FS-C). CONCLUSIONS: Conventional intraoperative ICGA underestimated perfusion in all cases. Warming the flap intraoperatively and achieving maximum vasodilation mitigates the effects of vasoconstriction and mimics the microcirculatory environment encountered at 24 h. Performing angiography after induced vasodilation improves ICGA assessment of flap perfusion.

The place of local/regional perforator flaps in complex traumas of the forearm.

BACKGROUND: Our aim was to conduct a retrospective study regarding the advantages of doing the all-in-one reconstruction in the same step with the debridement, and the possibility of using the local/regional perforator flaps to cover the tissue defects. METHODS: We reviewed a series of 137 cases from 1999 until now, for acute traumas with tissue defects of the forearm. We performed a regional perforator flap in 16 cases, and a local perforator flap in 121 cases. These flaps were used for both simple and complex defects coverage, including 26 cases with fractures and devascularization. RESULTS: The follow-up was between 2 months and 2 years. In all the cases the extremity was salvaged and an useful functional recovery was obtained. A very good evolution, with complete survival of the flap was recorded in 133 cases. We completely lost only one flap, and registered minor complications in three cases. CONCLUSION: The local perforator flaps represent a good and safe indication for small and medium defects in the forearm.